Function run_introspection 

pub fn run_introspection(
    credentials: &Credentials,
    dialect: Dialect,
    out_dir: &Path,
    init_metadata: bool,
    migrations_table: &str,
    migrations_schema: &str,
) -> Result<IntrospectResult, CliError>

Introspect a database and write schema/snapshot files

This is the main entry point for CLI introspection.